 No staffers will be allowed on stage. A two-minute answer to each question will be followed by a one-minute rebuttal and then a response to that rebuttal. CNN has agreed to mute the microphone of the candidate who isn't recognized to speak. And that particular aspect of the evening could be key, says ABC chief Washington correspondent Jonathan Karl. I think that the rules of this debate actually favor Donald Trump. The idea that the mics will be muted means that if he comes out of this and it's a relatively mild,